Anchors. I hate to do this but...

[noelex]

The angle that the chain makes over the bow roller, and the friction of the roller, has huge implications in these cases. In the loadcell measurements, a considerable load is taken on the bow roller. In the case of the pull by the anchor windlass, again much of the force is wasted on the bow roller.

So the force on the chain (and anchor) would be much greater than the loadcell measurements on the graph?
I would not have thought so at least in strong wind when the chain has a very shallow angle to bow roller, but it may explain the discrepancy between the graph and my impression of the forces involved (which can get quite scary in strong winds, you need to keep fingers and even limbs a long way from the chain when the wind is 50k.)

 

[Djbangi]

Vyv,

The load vs wind speed at anchor graph - I suspect there is some information missing, like rode length and depth to scope ratio. My understanding is that load to wind speed ought to be geometric as the load developed will increase by the square of the wind. Basically the graph is a straight line - but if the rode length had been veered to suit conditions then it would be shorter at low wind speed and longer at higher wind speed. Equally under benign conditions one could be further from shore but defintiely snuggle up in higher wind speeds. I'm not sure what a sailing scholl practice might be - but I would have thought snubbers would have been part of it.

In terms of the frictional; effect of chain. Under normal usage your chain is fixed at both ends and its friction sideways and the weight of the chain as your yacht moves fore and aft that is important. In fact if you were in enough tide, same direction as wind, and you are simply moving back and forth as gusts hit - then there is no firiction at all, your chain just lifts and falls. If you simply pull an untethered chain then it simply drags in its own smoothed out slot. Imagine 50m of chain on a beach - you can easily pull it behind you. Now tether one and try to pull it round in its own circle - accepting it might be difficult to find a big enough beach. I know its not under water but finding a 50m bit of beach shallow enough to try it is going to be difficult!

Good evening.

 

[CONGO]

Back again Richard,

Sorry about the jumbled mess but I will try to neaten it up this time, as you can see this caper is new to me. Beam, my terminology is boom but I suppose means the same, I should explain why the boom was developed, our original Sarca that was released in 1996 we found it to be an absolute breakthrough in anchor technology, Sarca quickly became a household name throughout Australia and N.Z.

We saved lives in the Tsunami that hit Phuket, the only boats that survived in the path of that tsunami were all on Sarca anchors, this is a fact of life some of their letters can be found not only in our web site, but originals can be found that were entered into the search engines.
So if our anchor was so good why did we develop the Super Sarca, the West Marine Test. Manson had just released their Supreme with Lloyds S/H/H/Power certification, Rocna also now on the market, Anchor Right U.K. yes we were getting established there two at the time, all of our anchors were then manufactured in N.Z.

The West Marine test warts and all pushed out a new market strategy, who has the highest holding power? Well after all this time it is still being debated, based on our passed record we did not believe we had to improve the Sarca any further.

So you all know the story, Sarca was a consistent performer it may have been down on holding power but their quote (if there was the best all round anchor Sarca comes close). Not a bad rap considering, I am sure there is a link between humans and anchors as I have never seen so many passionate debates, I suppose West Marines summery of the Sarca adds to the fray of this relationship, many will tell you consistency in hanging on can save many marriages.( That’s a tuffy for the opposition).

Sorry about all of that but a bit of humor in this forum surely can’t be harmful, so how do we improve the performance of the Sarca to catch up with this new S/H/H/Power revelation, after many months of trialing methods to aid us in measuring holding power we eventually came up with the boom, yes we recognized that the boom would pivot left to right but because the pull is dead center there is absolutely no leverage advantage.

Work it out yourself it’s not that hard, sure if the boom favors one anchor first it will slightly increase the other anchors speed, this increase we found to insignificant as we went on to develop the Sarca against Rocna and Supreme using this very device, when we first trialed the original Sarca against Rocna and Supreme our boom simply in all occasions favored our competitors, so in saying that, there was some consistency as to our findings recorded in the West Marine test.

We went on to develop Super Sarca and Sarca Excel deploying this very method, so does it work? Make one and try it yourself, but I think your question answers your doubt’s, Take a close look at the Vid in question, Super Sarca, Supreme and Rocna all start of sitting upright, the moment the boom moves forward both Rocna and Supreme fall on their side and Sarca immediately starts to bury, that is the advantage of inventing new concept, Super Sarca is convex our competitors are concave, a very clear view of the advantage of Super Sarca there.

The test area is consistent, have a good look at this vid, the substrate is black firm sand stone, if you were to dig this substance out and let it dry in the sun it will go so hard you could carve it. The only reason the boom is favoring the S/ Sarca is simply because the S/Sarca continues to dig down where the others are channeling out a trench. Now take a look at the second vid, Excel to the test, the boom this time clearly favor’s Supreme and Rocna, they are now being pulled slower than the Excel, watch what happens when the Excel starts to bury, does this explain your Question.

Yes Richard I am sure it’s not the be all and end all but it sure beats pulling anchors separately on a beach with a 4x4, if the 4x4 was hooked up to a beam and the substrate was consist ant I am that test would have been a whole lot more acceptable.
Hi Truscott, Look mate burying concrete blocks is simply not my style, further more I am too old to lift the bloody things. But thank you for your question.

Regards. Rex

 

[Brian@Fortress]

Greetings Rex Francis / Anchor Right

Good day Rex,

Glad to see you here in this thread. I have admired your company from a distance here in the US, as your passion for developing testing methods (T.A.T.S rig) as a means of further testing & improving your product is certainly commendable.

Our company owner shared that same passion, as recently I was looking through old archives with photographs and videos of him using bulldozers to pull anchors in the muddy swamps of the nearby Florida Everglades and along our beaches here in south Florida. He also developed a pull test simulation machine that was nicknamed "Black Maria," which held the flukes in place and the shank was pulled on until something gave.....and then it was back to the drawing board to strengthen that weakness.

I am intrigued by the development stages of your product line. Per your videos, you started out in the 90s with a concave roll bar design (similar to the current roll bar anchors), but then switched to a convex fluke design (similar to the older plow anchors) for the Super Sarca roll bar anchor.

Further still, by your impressive test results, it appears that with the Sarca Excel, you have taken the Delta design and improved upon it.....and this anchor is out-performing all of the other models.

I have seen your video about how the concave designs can hurt the environment vs. your convex anchor designs, but could you please also elaborate on the performance differences between the two designs that you discovered?

Many thanks!

Brian

 

[vyv_cox]

11mm nylon has a break load of about 3000Kg so its survival doesnt help prove or disprove the case that the load would only be 125Kg in a force 10 . Its hard to imagine the pictured chain hook failing with such a small force

Another example of the discrepancy I see is to look at a an anchor windlass fitted to a 33 foot yacht like this. It will have a maximum pull of about 1000Kg and a working load of about 350Kg.
If the 125Kg figure in a force 10 is accurate the anchor windless should be able to pull three 33 foot boats, tied in a row, comforably up to the anchor in a force 10 without the use of the main engine and still be within its working load (allowing a bit for friction on the bow roller) and nowhere near its maximum load.
This doesn’t fit with the observed performance in practice by a considerable margin and makes me skeptical of the figures in the graph.

I wasn't trying to prove anything with my snubber info, simply contrasting my experience with yours.

If you look at http://www.anchorwatch.co.uk/ you can see the expression derived by Prof. John Knox based on his measurements with Anchorwatch. My calcs using his expression give figures about twice that of the graph but still considerably lower than the theoretical ones of ABYC. Having sat out winds of force 9 on several occasions I have some doubts that my deck cleats would hold the loads predicted by ABYC.

Two authors who have also measured and calculated anchor rode loads are Skene and Robert Smith,(Anchors, Selection and Use). Both suggest loads in line with those of John Knox.

 

[Djbangi]

Anchor rode loads

Vyv

Should the graph not start start at around the weight of the chain, hanging off the bow, in no wind, say 5m, 8mm chain - about 8kg ish?

Though even if you 'recalibrate' the graph to accomodate so as to 'start' at 8kgs the loads are still insigificant compared with the loads quoted in the anchor 'holding capacity' articles.

However I note you say - something about 'sheltered anchorage' and a F7-8 is not my idea of sheltered!

I'm probably wrong and I am definitely confused.

 

[Ubergeekian]

However I note you say - something about 'sheltered anchorage' and a F7-8 is not my idea of sheltered!

I assume that "sheltered" means "from the waves", not "from the wind".

 

[noelex]

I wasn't trying to prove anything with my snubber info, simply contrasting my experience with yours.

If you look at http://www.anchorwatch.co.uk/ you can see the expression derived by Prof. John Knox based on his measurements with Anchorwatch. My calcs using his expression give figures about twice that of the graph but still considerably lower than the theoretical ones of ABYC. Having sat out winds of force 9 on several occasions I have some doubts that my deck cleats would hold the loads predicted by ABYC.

Two authors who have also measured and calculated anchor rode loads are Skene and Robert Smith,(Anchors, Selection and Use). Both suggest loads in line with those of John Knox.

The formula doesn’t look very realistic to me it seems to totally ignore the dynamic loads involved with the let out clause that” The force will be much larger if snatching occurs”
Nevertheless it predicts a much higher force than the graph 180Kg in 30K instead of 70Kg from the graph and 500Kg in 50K instead of 125kg from the graph.
This would seem to illustrate my belief that there is something wrong with the graphs figures.

 

[CONGO]

Hi Brian,
Great to hear from you, thanks for the question, there is nothing wrong with concave design until you put a hoop on them, the hoop acts like a back board and doesn’t allow the substrate to freely move through, if you look back in history and you wanted to sink a dam don’t try doing it with convex as you will never dig it out, concave will, we developed the original Sarca in a concave shape, sure it worked a treat dug in every time and we rarely drifted, back in those days we did not have winches on our trailer boats, my son at the time was twelve years old and for the first time could not pull the anchor up as it was most times absolutely packed full with weed and mud.

If we had any passion for the environment we certainly weren’t showing it with our concave design as many times we pulled it up, whatever we were anchored in came up with it.

This was we thought a huge breakthrough in anchor technology when we first developed it, you can imagine the disappointment, having the hoop on the rear just compounded the problem, we found our trip release to be of little benefit as the upturned edges of the concave grabbed and would not allow retrieval as we thought.

You know when you are out in the dark in dangerous waters it is not possible to dislodge this rubbish when retrieving concave design, because of the **** accumulated in the fluke sometimes we could not get the anchor to pull into the bow roller, any way that is all history now as we turned the Sarca into convex and soon learnt why our forefathers always used convex to dig in and concave to dig out.

We also noticed a margin of improvement as to the depth our Sarca would now penetrate compared to concave, furthermore our trip release was now doing what we had designed it for, as on retrieval the center of the convex plate was now in contact and allowed the anchor to readily slide out, what an improvement, ease of use, environmentally friendly, exceptional holding power and little to no mud.

Having said all of that there are many that have new generation concave anchor designs with hoops that will swear by them, there are many that will disagree with my findings and that’s fine, these new anchor designs are making them feel safer than ever before, anchor technology has come a long way like all technology, it’s no different with boat anchors.

At the end of the day we can test as much as we like, but the real test is how the anchor in question regardless of design works for you.
Our testing methods have certainly allowed us to produce better anchors; regardless whether we trial these on tugs boats, or pull them with our T.A.T.S. Rig , I believe we will never replicate what your anchor could be subject to in real life conditions.

No anchor Manufacturer should be making statements that you will never drag their anchor, I know there are a few that do, it is foolish and dangerous to make such statements.

Yachters anchoring overnight probably don’t come in contact with the rubbish a trailer boater would, they target heavy overburden types of substrate as that is where the fish are, so concave with a roll bar may not be as problematic for a yachter as it can be for a fisherman.

There has been much controversy over anchor strength and design, whilst that is important anchors will always be lost, bent, rust, can you imagine a 100 ton trawler powering over an anchor because it is wedged between rocks, he is in a hurry there is a storm on the way, he will either get lucky and pluck the anchor out or completely destroy it.

I have been honest with my findings and answered your question hopefully to your satisfaction.

Brian sorry for taking so long to reply, that goes for the others asking questions as well, but your forum doesn’t kick in here until about 9 .30 PM, with my typing skills I wouldn’t give up my day job.it is now 1 am so I will have to give it away until tomorrow.
Regards to all.
Rex.

 

[Twister_Ken]

All makes me think that if I was a student doing nautical studies, I know what I'd do my thesis on. Might take a while though!

 

[Sans Bateau]

Just joined this thread, I cant be bothered to read it all, there looks like some long posts. I suppose the Delta is considered very highly by the pundits. Delta is the one I have, I upgraded from a CQR, apparently they arnt very good. So TK, you need to buy a Delta.

 

[Rigger Mortice]

Sarca videos

Hi Rex,

I've been looking at your site and in particular the video "Next Generation Anchor Environment Destruction" at http://www.anchorright.com.au/sarca/video

A few quick questions

1. As you may have seen, we have constantly been told that cutting slots in metal causes problems with modern anchors. Unfortunately I have been unable to get any explanation about the nature of those "problems". Whether it is that the steel suddenly cracks, mysteriously bends, or even that the anchor spontaneously disintegrates and magically reappears in the next bay as a boiled egg, hasn't been explained.
As you have several slots in your product, I would be interested to hear what your views are.

2. I like the idea of the retrieval slot. However, when overnighting I would be worried about the anchor ending up the "wrong way" round following a turn of the tide.
Do you have any recommendation to avoid this problem?

3. In the video I think that you say that you made up your first prototype with the concave (Spade) blade way back in 1992....well before the other "new anchors" were introduced in the mid 2000's. Have I got that right?


Incidentally, I think its great that you have published copies of all the certificates which you have been given on your site. It makes it much easier to see exactly what you have been awarded.

 

[BelleSerene]

Just joined this thread, I cant be bothered to read it all, there looks like some long posts. I suppose the Delta is considered very highly by the pundits. Delta is the one I have, I upgraded from a CQR, apparently they arnt very good. So TK, you need to buy a Delta.

Yes, as everyone's been saying over these pages, Delta's the biz. You don't need to bother about these third-generation anchors.

TK, there's your solution mate.

 

[cliff]

Yes, as everyone's been saying over these pages, Delta's the biz. You don't need to bother about these third-generation anchors.

TK, there's your solution mate.

+1½

 

[Maine Sail]

The angle that the chain makes over the bow roller, and the friction of the roller, has huge implications in these cases. In the loadcell measurements, a considerable load is taken on the bow roller. In the case of the pull by the anchor windlass, again much of the force is wasted on the bow roller.

It must because I own a load cell and place it in front of the bow roller when measuring. This video is capturing peak loads in about 17-19 knots on a 36 foot sloop. The load data some of these folks claim do not match up with my own measurements which can be seen on video. This video is showing 218 pounds peak loads in 17-19 knots. I have physically recorded over 900 pounds peak loads on our 36 footer.

http://www.youtube.com/watch?v=y2oRFt5cX_0

 

[DavyMac]

Sarca Excel

Hi Rex

Thanks for coming on here and for the helpful explanations of your testing gear etc.

Your Excel anchor looks interesting and the test results are certainly promising, but can you explain how it differs from the Delta and why those differences make such a big difference in practice. The changes I can see from your photos are:

1. a slightly sharpened/blade style point (I would guess to ease penetration in harder bottoms);

2. the ears at the back of the flukes are angled out a little more (to provide more resistance?);

3. the flukes are concave in two dimensions - i.e. there is a flatter plate running longitudinally along the lower edge of the flukes (these appear in the Delta patent, which has been linked from here before, but where seemingly not put into production by Simpson Lawrence); and

4. there are holes in the flukes (which intuitively would decrease resistance).

Are you able to share the thinking or is it a trade secret?

 

[fishermantwo]

I would suspect the holes in the flukes are to unstick mud when recovering.

One other point that does not seem to have been covered is that these new anchors have to be attractive. If you have spent 1 or 2 million then you don't want an eye sore hanging off your bow roller. I notice that most of the large, expensive game boats locally have CQRs, they look unobstrusive but rarely anchor.

As I mentioned earlier, new generation anchors are the most stolen item from marine enviroments in Australia.

 

[Twister_Ken]

As I mentioned earlier, new generation anchors are the most stolen item from marine enviroments in Australia.

Australia, criminals, genetic innit.

 

[Djbangi]

Its ironic - but they inherited The Lucky Country, galling really. From all accounts they even have decent anchors. It makes you wonder if there is any justice.

 

[Marmalade]

Go on then - I'll do it. Well done Ken!

er what I meant was - Mine's a delta